Calculate density altitude instantly from field elevation, temperature, and altimeter setting. Essential for safe flight planning in hot, high, and humid conditions.
Click any scenario to load it into the calculator.
| Location | Elev | Temp | ~DA |
|---|---|---|---|
| Denver, CO (KDEN) | 5,430 ft | 95°F | 9,121 ft |
| Phoenix, AZ (KPHX) | 1,135 ft | 115°F | 5,262 ft |
| Sea Level, Standard Day | 0 ft | 59°F | 0 ft |
| Leadville, CO (KLXV) | 9,934 ft | 75°F | 13,362 ft |
| Dallas, TX (KDAL) — Humid | 487 ft | 100°F | 3,852 ft |
Try this sample question from the FAA Private Pilot Knowledge Test:
An airport at 6,000 ft elevation has an outside air temperature of 35°C and an altimeter setting of 29.80 inHg. What is the approximate density altitude?
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Start Free TrialDensity altitude is the altitude at which the air density matches standard atmospheric conditions (ISA). It is the single most important performance indicator for any piston or turbine aircraft, because your engine and wings perform as if they were at that altitude — regardless of your actual elevation.
Density altitude is calculated in three steps: (1) Pressure Altitude = Field Elevation + (29.92 - Altimeter Setting) x 1,000; (2) ISA Standard Temperature = 15°C - (PA x 0.00198); (3) Density Altitude = PA + 120 x (OAT - ISA Temp). Humidity can further increase density altitude.
Higher density altitude means longer takeoff rolls, reduced climb rates, and decreased engine power. A Cessna 172 at sea level needs about 1,600 ft for takeoff; at 8,000 ft density altitude, it needs about 3,000 ft. Normally aspirated engines lose approximately 3% power per 1,000 ft of density altitude.
Pilots memorize the "three H's" as the recipe for dangerously high density altitude: Hot (high OAT reduces air density), High (higher elevation means less dense air), and Humid (water vapor displaces oxygen molecules). When all three combine, aircraft performance is severely degraded.
Humid air is less dense than dry air because water vapor molecules are lighter than nitrogen and oxygen molecules. This calculator uses the dew point to estimate vapor pressure and apply a humidity correction. The effect can add several hundred feet to the density altitude on very humid days.
On a hot summer day at Denver International Airport (5,430 ft elevation), the air can behave as if the aircraft is at 8,000 to 9,000 ft. That means longer takeoff rolls, reduced climb rates, and decreased engine power output.
Step 1: Pressure Altitude
PA = Field Elevation + (29.92 - Altimeter Setting) x 1,000
Step 2: ISA Standard Temperature
ISA Temp = 15°C - (PA x 0.00198)
Step 3: Density Altitude
DA = PA + 120 x (OAT - ISA Temp)
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